package com.ddm.server.common.mongodb;

import java.lang.annotation.*;

@Target({ ElementType.TYPE })
@Documented
@Retention(RetentionPolicy.RUNTIME)
public @interface CompoundIndex {
    /**
     * The actual index definition in JSON format. The keys of the JSON document are the fields to be indexed, the values
     * define the index direction (1 for ascending, -1 for descending). <br />
     * If left empty on nested document, the whole document will be indexed.
     *
     * @return
     */
    String def() default "";

    /**
     * @return
     * @see <a href="https://docs.mongodb.org/manual/core/index-unique/">https://docs.mongodb.org/manual/core/index-unique/</a>
     */
    boolean unique() default false;

    /**
     * If set to true index will skip over any document that is missing the indexed field.
     *
     * @return
     * @see <a href="https://docs.mongodb.org/manual/core/index-sparse/">https://docs.mongodb.org/manual/core/index-sparse/</a>
     */
    boolean sparse() default false;

    /**
     * @return
     * @see <a href="https://docs.mongodb.org/manual/core/index-creation/#index-creation-duplicate-dropping">https://docs.mongodb.org/manual/core/index-creation/#index-creation-duplicate-dropping</a>
     * @deprecated since 2.1. No longer supported by MongoDB as of server version 3.0.
     */
    @Deprecated
    boolean dropDups() default false;

    /**
     * The name of the index to be created. <br />
     * <br />
     * The name will only be applied as is when defined on root level. For usage on nested or embedded structures the
     * provided name will be prefixed with the path leading to the entity. <br />
     * <br />
     * The structure below
     *
     * <pre>
     * <code>
     * &#64;Document
     * class Root {
     *   Hybrid hybrid;
     *   Nested nested;
     * }
     *
     * &#64;Document
     * &#64;CompoundIndex(name = "compound_index", def = "{'h1': 1, 'h2': 1}")
     * class Hybrid {
     *   String h1, h2;
     * }
     *
     * &#64;CompoundIndex(name = "compound_index", def = "{'n1': 1, 'n2': 1}")
     * class Nested {
     *   String n1, n2;
     * }
     * </code>
     * </pre>
     *
     * resolves in the following index structures
     *
     * <pre>
     * <code>
     * db.root.createIndex( { hybrid.h1: 1, hybrid.h2: 1 } , { name: "hybrid.compound_index" } )
     * db.root.createIndex( { nested.n1: 1, nested.n2: 1 } , { name: "nested.compound_index" } )
     * db.hybrid.createIndex( { h1: 1, h2: 1 } , { name: "compound_index" } )
     * </code>
     * </pre>
     *
     * @return
     */
    String name() default "";

    /**
     * If set to {@literal true} then MongoDB will ignore the given index name and instead generate a new name. Defaults
     * to {@literal false}.
     *
     * @return
     * @since 1.5
     */
    boolean useGeneratedName() default false;

    /**
     * If {@literal true} the index will be created in the background.
     *
     * @return
     * @see <a href="https://docs.mongodb.org/manual/core/indexes/#background-construction">https://docs.mongodb.org/manual/core/indexes/#background-construction</a>
     */
    boolean background() default false;
}
